The invention relates to apparatus for reforming deformed structures, and more particularly to apparatus for reforming and removing dents from large cargo containers which are made of steel panels, strengthened with alternate vertical lands and grooves.
Containerized cargo movement is relatively new and it involves the use of large containers which are modular structural units on a pallet-style base. In use, the cargo is packed into a container which is typically sealed. It is then transported by truck, railroad flat car, ship or a combination of the foregoing. For example, the container may initially be secured to the bed of a truck or trailer so as to provide a van-like vehicle. The truck may be used for carrying such containers to a railroad and there removed and secured to a flat car, or may be carried to a dock where the containers are removed and loaded as cargo on a ship. At the destination of the train or ship the containers once again may be placed upon trucks and carried to the destination of the cargo.
The containers are lifted, loaded and unloaded by various types of hoisting mechanisms and loading equipment. When being so lifted, loaded, and unloaded, and sometimes during travel, the containers may be damaged. They are usually are of the type having steel side walls strengthened by being formed of alternate lands and grooves. Side wall denting is the most common type of damage and it is the repair of this type of damage to which the present invention is applied.
Prior to my invention it was the practice to pound out the dents with hammers. Usually a crew of repairmen work together pounding out the deformation with hammers until the deformed region of a side wall is approximately reformed. One disadvantage of this method of repair is that the straightened region is unattractive because of the marks left by the hammers. A second disadvantage is that hammers work the metal so as to make it easier to be dented and if dented again, make it more susceptible to cracking.